Paper containers having barrier liner layers and closed by paper end members also having barrier liner layers for packaging various products, including food products, constitute a significant commercial consumer product.
These prior containers, as illustrated in FIGS. 4 and 5 of the drawings and generally designated at 10, conventionally include a generally tubular-shaped body member 12 having opposed ends 13 and including a paperboard layer 14 and a barrier liner layer 15. The tubular body member 12 may be formed by spiral or convolute winding of the layers 14, 15. This prior container 10 further includes a generally cup-shaped end member 20 having a radially-extending central portion 21 of generally the same configuration and dimensions as one of the ends 13 of the body member 12 and an axially-extending flange portion 22 around the outside of the central portion 21. This end member 20 also conventionally includes a paperboard layer 24 and a barrier liner layer 25 positioned on the outside of the cup-shaped end member so as to be positioned inside the container when the end member 20 is positioned within one end 13 of the tubular body member 12.
In these prior containers 10, the end member 20 is positioned in one end 13 of the tubular body member 12 with the flange portion 22 extending outwardly of the body member. The end 13 of the tubular body member 12 is inwardly-curled into a generally U-shaped cross sectional configuration around the outwardly-extending flange portion 22 of the end member 20. In this position, the barrier layer 25 of the end member 20 is in face-to-face position with the barrier layer 15 of the body member 12 on the outside of the cup-shaped end member 20. Bonding means 30 is positioned between the barrier liner layers 15, 25 in face-to-face relation on the outside of the cup-shaped end member 20. Bonding means 31 is positioned between the inside of the flange portion 22 of the end member 20 and the inside of the U-shaped configured end 13 of the body member 12. Both bonding means 30, 31 cooperate with the barrier liner layers 15, 25 to seal the one end of the container against leakage.
While this prior construction of a container 10 provided a sufficient seal at the end 13 of the body member 12 by the end member 20, problems were present with breaking of the seal if the container 10 is dropped or other abuse is caused to the container which creates an internal force in the direction of the arrow shown in FIG. 5. When this internal force is created, the end member 20 will be flexed downwardly relative to the body member 12 causing a rupture or tearing of the liner layer 15 of the body member 12 where it is bonded to the liner layer 25 of the end member 20 since the bonding means is stronger than the barrier liner layers. This compromises the seal in the one end 13 of the tubular body member 12 of the container 10 and thus allows undesirable leakage of the contents of the container.